The high aerodynamic noise induced by automotive air conditioning systems has important effects on the ride comfort, and the centrifugal fan is the largest noise source in these systems. It is very important to reduce...The high aerodynamic noise induced by automotive air conditioning systems has important effects on the ride comfort, and the centrifugal fan is the largest noise source in these systems. It is very important to reduce the aerodynamic noise generated by the centrifugal fan. The flow field and the sound field on the whole centrifugal fan configuration have been carried out using the computational fluid dynamics. Simulation results show that the sound pressure level near the outlet of the centrifugal fan is too high. Based on the relationship between flow characteristics and the aerodynamic noise, four parameters of the centrifugal fan, i.e., impeller blade＇s outlet angle 0, volute tongue＇s gap t, collector inclination angle fl, and rotating speed n, were selected as design variables and optimized using response surface methodology. While keeping the function of flow rate unchanged, the peak noise level is reduced by 8 dB or 10.8%. The noise level is satisfactorily reduced.展开更多
The volute tongue can split the gas in the multi-blade centrifugal fan to make the gas flow to the volute outlet as much as possible.However,the unsteady axial deflection of the gas in the impeller results in differen...The volute tongue can split the gas in the multi-blade centrifugal fan to make the gas flow to the volute outlet as much as possible.However,the unsteady axial deflection of the gas in the impeller results in different air flow angles at the outlet of the impeller at different blade heights.This seriously affects the flow near the volute tongue.The wave leading-edge structure of humpback whale flippers has a very high flow control effect under complex flow conditions.Therefore,the wave leading-edge structure is studied in this paper and applied to the optimization design of multi-blade centrifugal fan volute tongue.First,based on the wave leading-edge structure of humpback whale flippers,three-dimensional wave leading-edge airfoils with different wave direction angles are established to judge the adaptability of the new wave leading-edge structure under different attack angles.Then,aiming at the internal flow field and noise characteristics of multi-blade centrifugal fan,a bionic volute tongue optimization design method is proposed,and studied its influence on the internal flow field and noise characteristics of the fan.The results show that when the wave direction angle is 45°,the wave leading-edge structure can effectively suppress the generation of the leading-edge separation vortex and the shedding of the wake vortex,which is also helpful to reduce the noise.The bionic volute tongue with the wave leading-edge structure can adapt to the situation that the impeller outlet air flow angle is small.At the maximum volume flow rate operating point,the static pressure recovery coefficient of the bionic volute tongue fan is increased by about 5%compared to the original fan,the air volume is increased by 5.16%,and the noise is reduced by 0.6 dB.展开更多
基金Project(50975083) supported by the National Natural Science Foundation of ChinaProject(61075001) supported by China State Key Laboratory of Advanced Design and Manufacturing for Vehicle BodyProject(201-IV-068) supported by the Fundamental Research Funds for the Central Universities,China
文摘The high aerodynamic noise induced by automotive air conditioning systems has important effects on the ride comfort, and the centrifugal fan is the largest noise source in these systems. It is very important to reduce the aerodynamic noise generated by the centrifugal fan. The flow field and the sound field on the whole centrifugal fan configuration have been carried out using the computational fluid dynamics. Simulation results show that the sound pressure level near the outlet of the centrifugal fan is too high. Based on the relationship between flow characteristics and the aerodynamic noise, four parameters of the centrifugal fan, i.e., impeller blade＇s outlet angle 0, volute tongue＇s gap t, collector inclination angle fl, and rotating speed n, were selected as design variables and optimized using response surface methodology. While keeping the function of flow rate unchanged, the peak noise level is reduced by 8 dB or 10.8%. The noise level is satisfactorily reduced.
基金supported by the National Natural Science Foundation of China(11872289)“Aviation Engines and Gas Turbines”National Science and Technology Major Project Funding(J2019-IV-005-0072).
文摘The volute tongue can split the gas in the multi-blade centrifugal fan to make the gas flow to the volute outlet as much as possible.However,the unsteady axial deflection of the gas in the impeller results in different air flow angles at the outlet of the impeller at different blade heights.This seriously affects the flow near the volute tongue.The wave leading-edge structure of humpback whale flippers has a very high flow control effect under complex flow conditions.Therefore,the wave leading-edge structure is studied in this paper and applied to the optimization design of multi-blade centrifugal fan volute tongue.First,based on the wave leading-edge structure of humpback whale flippers,three-dimensional wave leading-edge airfoils with different wave direction angles are established to judge the adaptability of the new wave leading-edge structure under different attack angles.Then,aiming at the internal flow field and noise characteristics of multi-blade centrifugal fan,a bionic volute tongue optimization design method is proposed,and studied its influence on the internal flow field and noise characteristics of the fan.The results show that when the wave direction angle is 45°,the wave leading-edge structure can effectively suppress the generation of the leading-edge separation vortex and the shedding of the wake vortex,which is also helpful to reduce the noise.The bionic volute tongue with the wave leading-edge structure can adapt to the situation that the impeller outlet air flow angle is small.At the maximum volume flow rate operating point,the static pressure recovery coefficient of the bionic volute tongue fan is increased by about 5%compared to the original fan,the air volume is increased by 5.16%,and the noise is reduced by 0.6 dB.
